The use of camera devices with a single optical chain and sensor tends to limit the amount and type of optical information that can be captured as the result of the limitations of the single sensor and/or a fixed color filter incorporated into or associated with the sensor.
Many sensors include what is know as a Bayer filter. In a Bayer filter, more pixel elements are subject to a green filter while a lesser number of pixel elements are subjected to red and blue filters. This results in the sensor capturing more pixel values corresponding to the color green than the color red or blue. Given that the human eye is more sensitive to the color green, this has been considered a reasonable design choice with respect to many camera implementations.
Unfortunately, the capture of more green pixel values then red and blue pixel values results in a non-uniform amount of information being captured by the camera with respect to the three colors, Red (R), Green (G) and Blue (B) often captured as the basis of color images.
In addition, the use of conventional sensors with Bayer filters limits the information which can be captured by a sensor to R, G and B information since the filter over a pixel element will normally filter out light other than the R, G or B color to which the filter element over a pixel of a sensor corresponds.
While R, G and B light information is normally sufficient for normal photographs, it is sometimes desirable to capture broadband information such as that which can be captured without using a color filter over a pixel element of a sensor and in some cases it is desirable to capture IR information rather than R, G, B information, e.g., at night.
While using movable filters with the filters being changeable might seem like one approach to avoid being limited to the standard Bayer filter pattern, when the filters are to be aligned with individual pixel elements of a sensor such alignment can be difficult to achieve if a movable filter arrangement were attempted.
While a uniform filter may be placed over a sensor, e.g., to allow the sensor to detect light of a single color, such an approach requires different sensors for each color if a color image is to be captured and/or requires images to be captured at different times with the filter being changed between image capture periods.
In view of the above discussion it should be appreciated that there is a need for methods and apparatus which would allow a camera device to capture images without being constrained to using a single filter configuration or using separate sensor for each individual color. Furthermore, it would be desirable if the camera device did not require the use of movable filters for at least some applications with the camera device being able to capture different colors of light using an individual sensor in at least some applications.